As the media industry moves from a tape-based system of storing content to a digital file-based system of storing content, AS02 MXF was created as an industry specification for loosely-coupled storage of individual sequence of pictures and synchronizing them with audio. The AS02 MXF container system attempts to address the problem of having a common file format in a facility that has to handle many input formats and make many output formats. But these packages usually include encoded video essence data that may be difficult to analyze without decoding the essence data. AS02 MXF is one example of a video package, but other video packages and package standards have also been discussed and implemented by digital systems.
Content providers must meet certain industry specifications for the video and audio quality of the content they publish. The AS02 MXF wrapped content or other video packages may come from a variety of different sources, and the quality of each piece of content must be analyzed before publishing the content. One way to analyze video quality is to measure the peak signal-to-noise ratio (PSNR). The PSNR may be measured by comparing video essence in a package to a source version of the file. Using the PSNR, a content provider may be able to determine if the package meets industry specifications for video quality. A content provider may need to perform this quality analysis because the video package may have generational losses in video quality as a result of decoding and re-encoding video essence.
In order to measure the PSNR of the video essence in a package, such as an MXF package, the package must be unpackaged and decoded before the PSNR of an individual video frame can be determined. The unwrapping and decoding process may take a very long time, especially if the video package contains a lot of data. Further, the decoding process may be further complicated because video files may be presented in either progressive or interlaced video formats. As a result, measuring the PSNR for an individual frame of a video essence track may take a long time to discover and also require many keystrokes from an operator trying to measure the PSNR. Furthermore, a video file contains thousands of frames, depending on the length of the piece of content, and performing PSNR for the entire video file could take a very long time to perform for any skilled video editor.
As shown by all of the above discussed limitations, a tool is desired to overcome the limitations by quickly, easily, and automatically measuring a PSNR from a packaged video file.